Field of the Invention
The present invention relates to a lighting apparatus comprising: a light source; a sealed housing accommodating the light source therein; and an aiming screw rotatably supported in a through-hole which extends through the housing, wherein an optical axis of light emitted from the light source is adjusted by rotating the aiming screw.
Description of the Related Art
Japanese Utility Model Registration No. 2528745 has made publicly known an optical axis adjuster in which a male thread of an aiming screw is screwed to a nut that is provided to a reflector swingably supported inside a housing of a vehicle headlamp, and an optical axis is adjusted, by rotating the aiming screw so as to push and pull the housing.
Furthermore, Japanese Patent Application Laid-open No. 2002-193023 has made publicly known an optical axis adjuster including a synthetic resin-made aiming screw.
Japanese Patent No. 4517227 has made publicly known an optical axis adjuster including an air-permeable, water-proof and dust-proof filter which is provided to a breathing passage communicating inside and outside of a housing with each other in order to prevent that air pressure inside the housing changes due to heat generation and cooling of a light source of a vehicle headlamp so that moisture and dust outside the housing are sucked into the inside of the housing when the air pressure decreases.
Meanwhile, providing the breathing passage to the housing of the vehicle headlamp, as described in Japanese Patent No. 4517227, causes problems such as a structure of the housing becoming complicated, and dimensions of the housing becoming larger.